Guest, I'm no doctor, nor expert in any way about dreams. This is just my personal opinion:
Is there a reason why before cpap I used to dream all the time ( and a lot of times they were scary ones ) and now that I am on cpap I haven't had one dream. I have been on cpap for 2 months.
I think that is a very GOOD sign ....not
remembering your dreams now that you are on cpap treatment. You very likely are having dreams but are sleeping so soundly and so well that you are not having any apneas or hypopneas that could jolt you awake enough to actually be aware of (and remember) the dream like used to happen to you.
I thought that deep sleep stage was when you had dreams.
REM (rapid eye movement) sleep is where most dreaming occurs - REM is not the "deep" stages of sleep (Stage III and IV.) REM sleep is also where we are most apt to have events like apneas and hypopneas, so people who are awakened enough to remember lots of dreams throughout the night are likely being thrown up out of REM by an apnea. Not good.
The first REM sleep usually occurs about an hour and a half after we go to sleep. Throughout the night we get into REM several more times, with each REM time getting longer and longer. The longest REM period is usually just before we wake up in the morning. If something sudden (like an alarm clock) wakes us up in the morning, we're very likely to be awakened out of that last REM and might remember that last dream, or at least be vaguely aware that we were dreaming.
Otherwise,
not remembering our dreams seems to me to be a better sign of good, peaceful sleep. Not
remembering them doesn't mean you weren't dreaming a lot! Perhaps you're sleeping well straight through them, just like you should.